1. Field of the Invention
The present invention relates to an output port determining apparatus for determining an output port of data, and more particularly to an output port determining apparatus for determining an output port connected to a network which has a network address having the longest match for a node address.
2. Description of the Related Art
IP routers connect different networks with each other in order to perform packet communications between those connected networks. Specifically, an IP router analyzes the header of a packet communicated between the connected networks, and selects a network route for the packet based on the IP address contained in the header.
The IP router searches for a network address which has the longest match for the IP address and transmits the packet through a shortest communication route for high-speed packet communications. The network address which has the longest match for the IP address is searched for by a software-implemented process or a hardware-implemented facility. One hardware apparatus for performing longest-match searching is disclosed in Japanese laid-open patent publication No. 11-261647.
The conventional apparatus for performing longest-match searching employs a Content Associated Memory (CAM) which performs processing operations for searching for a network address based on a longest match, which arises, however, a problem of making its hardware arrangement more complex.